Lawn-mower sharpener



Patented Oct. 25, I898.

Z. T. BUSH.

LAWN MOWER SHARPENER.

(Application filed Sept. 19. 1895.\

(N0 Model.)

INVE N 70/? Z \7. BY

A TTORNEY.

TNE NORRIS PEYEHS co. PHOYO-UIHO., WASNINGTUN. u. c

supports mounted in said bar, of an arm ex- UNITED STATES PATENT OFFICE.

ZACI'IARIAII T. BUSII, OF GRAND RAPIDS, MICHIGAN, ASSIGNOR OF ONE- IIALFTO MATTIIEVV BUSH,

OF OQRUNNA, MICHIGAN.

LAWN-MOWER SHARPENER.

SPECIFICATION forming part of Letters Patent No. 612,820, dated October25, 1898.

Application filed September 19, 1895. Serial No. 562.997. (No model.)

To all whom it may concern:

Be it known that I, ZACHARIAH T. BUSH, a citizen of the United States,residing at Grand Rapids, in the county of Kent and State of Michigan,have invented certain new and useful Improvements in Lawn-MowerSl1arpeners; and I do hereby declare the following to be a full, clear,and exact description of the invention, such as will enable othersskilled in the art to which it appertains to make and use the same.

My invention relates to improvements in devices for sharpening therotary blades of lawn-mowers without requiring the removal of the bladesfrom the mowing-machine; and the object that I have in View is toprovide an improved implement which may be applied to the mower-machineto have the pitch of the gage adjusted in angular operative re lation tothe mower-blades, thus making the implement applicable to lawn-mowers ofdifferent sizes.

With this end in view the invention consists in the combination, withasharpener-bar having an abrading-surface and adjustable tendingoutwardly from the bar and an adjustable support carried by saidprojecting arm and adapted to be moved to adjust the abrading-surface atthe proper pitch or angle with relation to the path of the rotarymowerblades; and the invention further consists in the construction andnovel combination and arrangement of parts, as will be hereinafter morefully described and claimed.

To enable others to understand my invention, I have illustrated the samein the accompanying drawings, forming a part of this specification, andin which- Figure 1 is a perspective view of the improved sharpenerimplement. Fig. 2 is an end View illustrating the implement applied inoperative relation to the shear-plate and one of the rotary blades of alawn-mowing machine.

Like letters of reference denote like parts in each of the figures.

The implement constructed in accordance with my invention consists of abar 13, a handle A, attached centrally to the bar, an abradin g-surfaceC,adj ustable supports D,attached to said bar B, a horizontal arm E,extending outwardly from said bar, and an adjustable support E, carriedby said projecting arm.

The barB is made, preferably, of hard wood of suitable dimensions,although the particular material and size of the bar are not important.On the inner lower side of the bar is formed a longitudinal recesss B,the vertical face of which constitutes a rest orholder for theshear-plate of the mowing-machine to bear against when the instrument isin use. Forward of this recess is a downwardly-projectin g flange, whichforms the front wall of the recess, and the lower edge of this flange isinclined upwardly and produces the inclined face B, to which is securelyfastened the abrading-plate C. This abrading-plate is of suitablematerial for sharpening steel blades, preferably a hard grittysubstance, such as emery, and said abrading-plate is fastened to theinclined face B of the sharpener-bar in any suitable way, so that thesaid plate C partakes of the inclination or pitch of the flange on thelower side of the sharpener-bar.

The handle A is attached centrally in a suitable way to the upper sideof the sharpener-bar B, and on opposite sides of this handle and nearthe ends of I the sharpener-bar the adjustable supports Dare provided towork in suitable openings in the sharpenerbar B. These adjustablesupports D consist, preferably, of adj usting-screws, which are providedwith suitable heads at their upper ends for convenient manipulation byhand, and the lower ends of said adjusting-screws extend into thelongitudinal recess B of the sharpener-bar B. y

The arm E occupies a horizontal position substantially at right anglesto the length of the sharpener-bar B, and this arm E is fitted looselyin a socket or opening provided in the rear side of the sharpener-bar B,so that the horizontally-projecting arm is adjustable in said bar and isextensible in relation thereto. Said projecting arm is designed to beclamped rigidly and adj ustably in place by a set-screw E, which finds abearing in a suitable threaded aperture in the bar B and has its innerend arranged to impinge against the arm E. This horizontally projectingand adjustable arm is provided near its outer end with a verticalthreaded opening to receive the threaded shank of the adjusting-screw E,which constitutes the adjustable support carried by the arm E. i

It will be seen by reference to Fig. 1 that the ends of the threeadjusting-screws are placed at the points of a triangle and that theinstrument rests on the points of the screws, the latter thus formingracks for the support of the device when in use. By the employment ofthe adj usting-screw E at the apex of the triangle formed by the threescrews D, D, and E the instrument may be adjusted on the points of thescrews D D for the purpose of raising or lowering the bar B and theplate 0 thereon, whereby the faces B and C may be adjusted vertically,more or less, as may be desired, to regulate the pitch of the abrasivesurface 0 with relation to the path of the mower-blades.

To sharpen a lawn-mower with this instrument, I first invert the mowerand place it in a box or other suitable support, leaving thetraction-wheels of the machine free to revolve, after which the mower isset so that the rotary blades will revolve freely without touching theshear-plate, leaving plenty of room-say one-eighth of an inch-betweenthe cutting edges of the blades and the edge of the shear-plate. Thesharpener instrument is grasped by the handle A and placed on the bottomof the inverted shear-plate, so that the ends of the three set-screwsrest on the end surface of the shear-plate, and thedownwardly-projecting flange of the bar B abuts against the end edge ofsaid shearplate to have the abrading-plate O occupy a positionsubstantially in the path of the mower-blades. After the implement hasbeen thus applied the adj ustin g-screws are rotated to give theimplement a proper elevation, so that the abrading-plate will just clearthe rotary mower-blades, and by means of the adjusting-screw E, I givethe implement the proper pitch to bring the face of the abrading-plate 0parallel to the cutting edges of the blades. When the pitch is soproperly adjusted, the implement is lowered by adjusting the screws D,D, and E until the face of the abrading-plate G is brought into properfrictional contact with the cutting edges of the blades. Thedrive-wheels of the lawn mower are'now rotated to cause the bladesthereof to rotate in front of and the faces of their cutting edges tobrush frictionally against the face of the abrading-plate O, and

at the same time I move the instrument resting on the points of thethree screws longitudinally on the shear-plate from one end of theshear-plate to the other end thereof, the adjusting-screws serving assupports to the sharpener instrument and the vertical shoulder of therecess forminga guide against the edge of the shear-plate to properlydirect the sharpener instrument in its endwise movements along themower. In this relation the adjusting-screw E determines the gage ofpitch of the abrading-plate 0, thus causing the instrument to passlengthwise of the rotary blades and grinding and sharpening their edgesuniformly from one end to the other. By adjusting the set-screws asrequired the mower-blades may be ground more or less and the edges ofthe blades may be made as sharp as desired. 7

I am aware that slight changes in the form, proportion, and minordetails of construction may be resorted to without departing from thespirit or sacrificing any of the advantages of this invention.

Having thus described my invention, what I claim is- 1. In a lawn-mowersharpener, the combination with a recessed bar carrying anabrading-plate and adjustable supports for said bar, of arearwardly-projecting arm attached to said bar, and an adjustablesupport carried by said rearwardly-projecting arm, substantially asdescribed, for the purposes set forth.

2. The combination with a sharpener-bar having frictionally-adj ustablesupports, of an arm extending outwardly from said bar, and an adjustablesupport carried by said arm, substantially as described, for thepurposes set forth.

3. The combination with a sharpener-bar provided with anabrading-surface and adj ustable supports mounted in said bar, of anadjustable arm fitted to the sharpener-bar to extend rearwardlytherefrom, means for clamping said adjustable arm in fixed relation tosaid bar, and an adjustable support mounted in the arm and arranged in aposition intermediate between the adjustable supports on thesharpener-bar, substantially as and for the purposes described.

In testimony whereof I affix my signature in presence of two witnesses.

ZAOHARIAH T. BUSH.

Witnesses:

PORTER M. LATHROP, DENNIS L. ROGERS.

